While no official complaint has been made by TV chef Nigella, 53, police are likely to question the couple.

For many, it’s shocking that, had these pictures not been published, Saatchi might never have been challenged about his ­behaviour. It raises wider questions about our role as onlookers.

Dundee psychologist Dr Andrina McCormack, who has worked with victims of domestic violence, says aggressive acts in public are often about control.

She said: “Whether you’re a millionaire or on the dole, aggressive acts in public are sometimes about humiliation and controlling someone else.

Nigella Lawson

“The central issue is the control of another person and interfering with their personal space and dignity, and nobody has the right to do that.”

Lily Greenan, manager of Scottish Women’s Aid, hopes the incident will help inform the public about what is unacceptable behaviour.

She said: “Several people who were witnesses spoke to the press afterwards but didn’t feel able to ­intervene at the time, which is disheartening.

“I hope people can understand you can challenge this behaviour. We all have different definitions of playful but the descriptions of what happened don’t sound like play.”

Graham Goulden, chief inspector of Scotland’s Violence Reduction Unit (VRU), believes if men behave ­aggressively towards their partner in public, it raises serious questions about what goes on in the home.

He said: “I can’t comment on this specific incident but if someone is behaving in an aggressive way in public, what’s actually taking place in the house?

“If a man has the confidence or ability to do that in a public place, what is he doing in a private setting?

“Most men are law abiding and caring but there are a few who get a sense of privilege and power from our silence and lack of intervention.

“Even the silly sexist joke – it may sound like political correctness gone wrong but we know where this ­acceptance can lead to.

“We have a lot of young girls in society who see being hit and controlled as part of a relationship and that’s something we need to change.”

The VRU are leading a Mentors in Violence Prevention project in schools to encourage bystanders to act against abuse rather than ignore it – something that empowers the abuser.

Goulden said: “The police service in Scotland have domestic abuse as a top priority because if we can’t stop violence in the home, how are we going to stop it in the street?

“So we can do great work in investigating offences and supporting victims but we need to change attitudes and send a message that public aggression is not acceptable.

“If you see something that’s wrong, if you do nothing you send the message to the ­perpetrator that what is being done is okay and contribute to a society where violence is accepted.

“We need to understand why bystanders don’t get involved and it’s usually because they’re scared, they don’t want to make the situation worse, so it’s about giving people knowledge about how to intervene.”

Goulden believes how we talk about domestic violence – often attributing aggressive acts to being part of a “row” – also needs to change.

“It isn’t a row,” he said. “That’s part of the problem, it’s not a row, it’s a violent act. We need to look at what we as men can do to step up to the plate to challenge other men – our friends, family – about their behaviour.”

He suggests there are ways of speaking out to stop violence, without aggravating a situation, if people don’t feel comfortable getting involved.

He added: “If you can achieve a distance from the situation and shout to let them know you’re watching, that can often be enough to stop it.

“You could speak to the victim ­afterwards, to make sure they are okay, or the perpetrator afterwards if they’re known to you.

“But if you see violence or hear it, you phone the police as a basic minimum – and be assured that Police Scotland will attend, they’ll investigate and there’ll be support for the victim.

“Silence is violence. If you see ­something and hear something and walk away, you are telling the victim they’re on their own.”